<!DOCTYPE html>
<html>
<head>
    <title>Function Arguments Example 1</title>
    <script type="text/javascript">
        function addTen(num) {
            num += 10;
            return num;
        }
        
        var count = 20
        var result = addTen(count);
        alert(count);    //20
        alert(result);   //10

    </script>
</head>
<body>

</body>
</html>